1. Field of the Invention
The present invention relates to a recording medium, such as an optical disc, and a reproducing apparatus thereof.
2. Description of the Related Art
Generally, management information is recorded on an optical disc. The management information manages data (files) recorded on the optical disc. As a representative example, management information defined as ISO-9660 standard is known. The management information includes at least ID information and the size of each disc, the number and reproducing order of discs that correlate, and the ID information, the record position, and the size of each file recorded on the disc as structural elements.
However, in recent years, discs that have the management information corresponding to the ISO-9660 standard are categorized as various types such as specific discs, single-sided discs, and double-sided discs. However, the conventional management information does not include information that distinguishes such disc types.
The management information is especially important for system operation. In other words, if the management information is damaged, the entire information on the disc will be lost. To prevent such a problem, the same management information is recorded in another region as a spare. To further improve the safety of the management information, as shown in FIG. 40, the spare management information is recorded in a multiplexed fashion at multiple regions on the disc. However, in this case, the spare management information is recorded at a different record position as shown by arrows A. Thus, each portion of duplicated management information will have a different value that represents the position thereof. Thus, as the number of regions of the spare management information is increased, the work load of the disc provider increases.
Moreover, in recent years, as the storage capacity of optical discs increases, discs that record a plurality of stories with slightly different contents and that reproduce any story selected by the user are known. However, in this case, since the same data for each story is recorded in a multiplexed fashion, the efficiency of the disc storage capacity is remarkably low.
Furthermore, in recent years, as a technique for selectively reproducing a variety of data recorded on the disc, menus are used. When menus are composed, for example, as shown in FIG. 41, a menu list and memory image information are recorded at predetermined regions of the disc. In the menu list, the record position of menu image information corresponding to each menu number and the file record position corresponding to each menu selection number are recorded. When any menu number is selected (at step 1), a corresponding menu image information is read (at step 3) based on an address on the menu list (at step 2). Thus, the menu screen is displayed. When any file number is selected from the menu screen (at step 4), the record position of the desired file is determined corresponding to the menu list (at step 5) and the desired file is reproduced (at step 6).
However, in the above-described method using the menu list, as the number of selection items increases, the size of the menu list increases and thereby the ratio of the data amount of the menu to the entire record data amount increases, thereby lowering the efficiency of the disc storage capacity.